FOREST RESEARCH NOTE

NORTHEASTERN FOREST EXPERIMENT STATION 

Upper Darby , Pennsylvania 

No0 49 

1955 

Olldfire 

In A Young Stand Of Virginia Pine And Hardwoods 

Fire has often been used as a silvicultural tool in 

a managing most of the southern pines. At present, however, 

there is not' enough evidence to show whether similar techniques can be used in Virginia pine stands, The purpose of 

this note is to offer some observations on how a wildfire 

affected a young pine-oak stand, 

In November 1952, a hot surface fire ran through a 

30-year-old pine-hardwood stand near Beltsville, Maryland. 

This- fire started about 2 porn, on a high-hazard day. The 

fire danger station readings were as follows: fuel moisture, 

8 percent; wind, 15 m.p, h. ; and burning index 65 (based on 

100-point Fire Danger Meter 5-w). ~hirt~-five days had 

elapsed since the last rain of more than inch. The fire 

was controlled after it had covered about 5 acres, 

Effects Of Fire Stu~ed * In May 1953, four' 1120-acre plots were established, 

three in the bhrned-over area, and one in the adjacent' unburned stand. A 100-percent inventory was made of all trees 

0.5 inch doboho and larger on each of the four sample plots. 

A similar inventory was made in June 1954. Witkin 

each plot two pwmanent milacres were established* The,s e 

milacres were purposely located to sample the best catch of 

pine reproduction on each plot so that subsequent survival 

counts could be made, 

In March 1955, four temporary milacres were established at random in both the burned and unburned p~rtions of 

the study area. These randomly selected milacres provided a 

rough estimate of the number of Virginia pine seedlings 

present on both areas 28 months after the fire. 

Results to date show that this wildfire killed many 

trees. On the burned plots the original stand averaged 

1 
1,353 trees per acre. During the 2-year period following 

the fire, 613 (45 percent) of these trees died. Over half 

of the dead trees succumbed during the first year after the 

burno However, most of the fire-killed hardwoods resprouted 

following the burn, 

The stand on the unburned plot averaged 1,200 trees 

per acre, Mortality on this plot during the same 2-year 

period amounted to 15 percent of the original stand, 

Approximately two-thirds of the total number of trees 

on all plots were in the 1- to 4-inch d,b.h. classo Ninetysix percent of the dead trees also occurred in this same diameter range, 

More Seedlings In Burned Area 

2$ years after the fire there were 10,750 pine seedlings per acre on the burned area, but only 250 per acre on 

the unburned area. This seedling ratio of approximately 40 

to 1 mas found on both the temporary and permanent milacres. 

Most of these seedlings became established the second spring 

(1954) after an exceptionally good cone crop in 1953. Survival counts showed that the heaviest seedlingmortality 

took place during the first few months after germination. 

All seedlings alive in November 1953 were still living in 

November 1954. 

The large differences in seedling establishment between the burned and unburned plots may be due to several 

causes. Following the fire, the average depth of litter on 

the burned plots was 1.7 inches. On the unburned plot it 

was 263 incheso This reduetion in litter depth, pa~ieularly 

of hardwood leaves, would make it easier for seed to get 

down to where moisture conditions are better, The fire also 

killed many small-sized trees. This caused a reduction in 

the mount of shade on the unburned plots, Also, some of 

the surface roots were probably killed. 

A11 these factors improved conditions for better 

germination and survival of Virginia pine seedlings, Ultimate survival will depend upon the competition from both the 

remaining overstory and the prolific hardwood sprouts, 

Virginia Pi ne-Hardwood Research Center 

Northeastern Forest Experiment Station 

Forest Service, U.S, Dept, Agriculture 

Agriculture-Forest Service-Upper Darby